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  1. Feb 01, 2021
  2. Nov 15, 2020
  3. Jul 21, 2020
  4. Jul 10, 2020
    • Markus Armbruster's avatar
      error: Eliminate error_propagate() with Coccinelle, part 1 · 668f62ec
      Markus Armbruster authored
      
      When all we do with an Error we receive into a local variable is
      propagating to somewhere else, we can just as well receive it there
      right away.  Convert
      
          if (!foo(..., &err)) {
              ...
              error_propagate(errp, err);
              ...
              return ...
          }
      
      to
      
          if (!foo(..., errp)) {
              ...
              ...
              return ...
          }
      
      where nothing else needs @err.  Coccinelle script:
      
          @rule1 forall@
          identifier fun, err, errp, lbl;
          expression list args, args2;
          binary operator op;
          constant c1, c2;
          symbol false;
          @@
               if (
          (
          -        fun(args, &err, args2)
          +        fun(args, errp, args2)
          |
          -        !fun(args, &err, args2)
          +        !fun(args, errp, args2)
          |
          -        fun(args, &err, args2) op c1
          +        fun(args, errp, args2) op c1
          )
                  )
               {
                   ... when != err
                       when != lbl:
                       when strict
          -        error_propagate(errp, err);
                   ... when != err
          (
                   return;
          |
                   return c2;
          |
                   return false;
          )
               }
      
          @rule2 forall@
          identifier fun, err, errp, lbl;
          expression list args, args2;
          expression var;
          binary operator op;
          constant c1, c2;
          symbol false;
          @@
          -    var = fun(args, &err, args2);
          +    var = fun(args, errp, args2);
               ... when != err
               if (
          (
                   var
          |
                   !var
          |
                   var op c1
          )
                  )
               {
                   ... when != err
                       when != lbl:
                       when strict
          -        error_propagate(errp, err);
                   ... when != err
          (
                   return;
          |
                   return c2;
          |
                   return false;
          |
                   return var;
          )
               }
      
          @depends on rule1 || rule2@
          identifier err;
          @@
          -    Error *err = NULL;
               ... when != err
      
      Not exactly elegant, I'm afraid.
      
      The "when != lbl:" is necessary to avoid transforming
      
               if (fun(args, &err)) {
                   goto out
               }
               ...
           out:
               error_propagate(errp, err);
      
      even though other paths to label out still need the error_propagate().
      For an actual example, see sclp_realize().
      
      Without the "when strict", Coccinelle transforms vfio_msix_setup(),
      incorrectly.  I don't know what exactly "when strict" does, only that
      it helps here.
      
      The match of return is narrower than what I want, but I can't figure
      out how to express "return where the operand doesn't use @err".  For
      an example where it's too narrow, see vfio_intx_enable().
      
      Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
      confused by ARMSSE being used both as typedef and function-like macro
      there.  Converted manually.
      
      Line breaks tidied up manually.  One nested declaration of @local_err
      deleted manually.  Preexisting unwanted blank line dropped in
      hw/riscv/sifive_e.c.
      
      Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
      Reviewed-by: default avatarEric Blake <eblake@redhat.com>
      Message-Id: <20200707160613.848843-35-armbru@redhat.com>
      668f62ec
    • Markus Armbruster's avatar
      error: Avoid unnecessary error_propagate() after error_setg() · dcfe4805
      Markus Armbruster authored
      
      Replace
      
          error_setg(&err, ...);
          error_propagate(errp, err);
      
      by
      
          error_setg(errp, ...);
      
      Related pattern:
      
          if (...) {
              error_setg(&err, ...);
              goto out;
          }
          ...
       out:
          error_propagate(errp, err);
          return;
      
      When all paths to label out are that way, replace by
      
          if (...) {
              error_setg(errp, ...);
              return;
          }
      
      and delete the label along with the error_propagate().
      
      When we have at most one other path that actually needs to propagate,
      and maybe one at the end that where propagation is unnecessary, e.g.
      
          foo(..., &err);
          if (err) {
              goto out;
          }
          ...
          bar(..., &err);
       out:
          error_propagate(errp, err);
          return;
      
      move the error_propagate() to where it's needed, like
      
          if (...) {
              foo(..., &err);
              error_propagate(errp, err);
              return;
          }
          ...
          bar(..., errp);
          return;
      
      and transform the error_setg() as above.
      
      In some places, the transformation results in obviously unnecessary
      error_propagate().  The next few commits will eliminate them.
      
      Bonus: the elimination of gotos will make later patches in this series
      easier to review.
      
      Candidates for conversion tracked down with this Coccinelle script:
      
          @@
          identifier err, errp;
          expression list args;
          @@
          -    error_setg(&err, args);
          +    error_setg(errp, args);
               ... when != err
               error_propagate(errp, err);
      
      Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
      Reviewed-by: default avatarEric Blake <eblake@redhat.com>
      Message-Id: <20200707160613.848843-34-armbru@redhat.com>
      dcfe4805
    • Markus Armbruster's avatar
      qapi: Use returned bool to check for failure, manual part · 14217038
      Markus Armbruster authored
      
      The previous commit used Coccinelle to convert from checking the Error
      object to checking the return value.  Convert a few more manually.
      Also tweak control flow in places to conform to the conventional "if
      error bail out" pattern.
      
      Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
      Reviewed-by: default avatarEric Blake <eblake@redhat.com>
      Reviewed-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
      Message-Id: <20200707160613.848843-20-armbru@redhat.com>
      14217038
    • Markus Armbruster's avatar
      qapi: Use returned bool to check for failure, Coccinelle part · 62a35aaa
      Markus Armbruster authored
      
      The previous commit enables conversion of
      
          visit_foo(..., &err);
          if (err) {
              ...
          }
      
      to
      
          if (!visit_foo(..., errp)) {
              ...
          }
      
      for visitor functions that now return true / false on success / error.
      Coccinelle script:
      
          @@
          identifier fun =~ "check_list|input_type_enum|lv_start_struct|lv_type_bool|lv_type_int64|lv_type_str|lv_type_uint64|output_type_enum|parse_type_bool|parse_type_int64|parse_type_null|parse_type_number|parse_type_size|parse_type_str|parse_type_uint64|print_type_bool|print_type_int64|print_type_null|print_type_number|print_type_size|print_type_str|print_type_uint64|qapi_clone_start_alternate|qapi_clone_start_list|qapi_clone_start_struct|qapi_clone_type_bool|qapi_clone_type_int64|qapi_clone_type_null|qapi_clone_type_number|qapi_clone_type_str|qapi_clone_type_uint64|qapi_dealloc_start_list|qapi_dealloc_start_struct|qapi_dealloc_type_anything|qapi_dealloc_type_bool|qapi_dealloc_type_int64|qapi_dealloc_type_null|qapi_dealloc_type_number|qapi_dealloc_type_str|qapi_dealloc_type_uint64|qobject_input_check_list|qobject_input_check_struct|qobject_input_start_alternate|qobject_input_start_list|qobject_input_start_struct|qobject_input_type_any|qobject_input_type_bool|qobject_input_type_bool_keyval|qobject_input_type_int64|qobject_input_type_int64_keyval|qobject_input_type_null|qobject_input_type_number|qobject_input_type_number_keyval|qobject_input_type_size_keyval|qobject_input_type_str|qobject_input_type_str_keyval|qobject_input_type_uint64|qobject_input_type_uint64_keyval|qobject_output_start_list|qobject_output_start_struct|qobject_output_type_any|qobject_output_type_bool|qobject_output_type_int64|qobject_output_type_null|qobject_output_type_number|qobject_output_type_str|qobject_output_type_uint64|start_list|visit_check_list|visit_check_struct|visit_start_alternate|visit_start_list|visit_start_struct|visit_type_.*";
          expression list args;
          typedef Error;
          Error *err;
          @@
          -    fun(args, &err);
          -    if (err)
          +    if (!fun(args, &err))
               {
                   ...
               }
      
      A few line breaks tidied up manually.
      
      Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
      Reviewed-by: default avatarEric Blake <eblake@redhat.com>
      Reviewed-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
      Message-Id: <20200707160613.848843-19-armbru@redhat.com>
      62a35aaa
  5. May 27, 2020
  6. May 15, 2020
    • Markus Armbruster's avatar
      qom: Drop parameter @errp of object_property_add() & friends · d2623129
      Markus Armbruster authored
      
      The only way object_property_add() can fail is when a property with
      the same name already exists.  Since our property names are all
      hardcoded, failure is a programming error, and the appropriate way to
      handle it is passing &error_abort.
      
      Same for its variants, except for object_property_add_child(), which
      additionally fails when the child already has a parent.  Parentage is
      also under program control, so this is a programming error, too.
      
      We have a bit over 500 callers.  Almost half of them pass
      &error_abort, slightly fewer ignore errors, one test case handles
      errors, and the remaining few callers pass them to their own callers.
      
      The previous few commits demonstrated once again that ignoring
      programming errors is a bad idea.
      
      Of the few ones that pass on errors, several violate the Error API.
      The Error ** argument must be NULL, &error_abort, &error_fatal, or a
      pointer to a variable containing NULL.  Passing an argument of the
      latter kind twice without clearing it in between is wrong: if the
      first call sets an error, it no longer points to NULL for the second
      call.  ich9_pm_add_properties(), sparc32_ledma_realize(),
      sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize()
      are wrong that way.
      
      When the one appropriate choice of argument is &error_abort, letting
      users pick the argument is a bad idea.
      
      Drop parameter @errp and assert the preconditions instead.
      
      There's one exception to "duplicate property name is a programming
      error": the way object_property_add() implements the magic (and
      undocumented) "automatic arrayification".  Don't drop @errp there.
      Instead, rename object_property_add() to object_property_try_add(),
      and add the obvious wrapper object_property_add().
      
      Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
      Reviewed-by: default avatarEric Blake <eblake@redhat.com>
      Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Message-Id: <20200505152926.18877-15-armbru@redhat.com>
      [Two semantic rebase conflicts resolved]
      d2623129
  7. Feb 20, 2020
  8. Jan 24, 2020
  9. Aug 16, 2019
  10. Jun 12, 2019
  11. Nov 06, 2018
    • Marc-André Lureau's avatar
      nvdimm: set non-volatile on the memory region · 640713d8
      Marc-André Lureau authored
      
      qemu-system-x86_64 -machine pc,nvdimm -m 2G,slots=4,maxmem=16G -enable-kvm -monitor stdio -object memory-backend-file,id=mem1,share=on,mem-path=/tmp/foo,size=1G -device nvdimm,id=nvdimm1,memdev=mem1
      
      HMP info mtree command reflects the flag with "nv-" prefix on memory type:
      
      (qemu) info mtree
      0000000100000000-000000013fffffff (prio 0, nv-i/o): alias nvdimm-memory @/objects/mem1 0000000000000000-000000003fffffff
      
      (qemu) info mtree -f
      0000000100000000-000000013fffffff (prio 0, nv-ram): /objects/mem1
      
      Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
      Message-Id: <20181003114454.5662-3-marcandre.lureau@redhat.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      640713d8
  12. Oct 24, 2018
  13. Aug 10, 2018
  14. Jun 28, 2018
  15. May 23, 2018
  16. Mar 02, 2018
  17. Jan 19, 2018
  18. Aug 22, 2017
    • Thomas Huth's avatar
      hw/ppc/spapr: Fix segfault when instantiating a 'pc-dimm' without 'memdev' · 04790978
      Thomas Huth authored
      
      QEMU currently crashes when trying to use a 'pc-dimm' on the pseries
      machine without specifying its 'memdev' property. This happens because
      pc_dimm_get_memory_region() does not check whether the 'memdev' property
      has properly been set by the user. Looking closer at this function, it's
      also obvious that it is using &error_abort to call another function - and
      this is bad in a function that is used in the hot-plugging calling chain
      since this can also cause QEMU to exit unexpectedly.
      
      So let's fix these issues in a proper way now: Add a "Error **errp"
      parameter to pc_dimm_get_memory_region() which we use in case the 'memdev'
      property has not been set by the user, and which we can use instead of
      the &error_abort, and change the callers of get_memory_region() to make
      use of this "errp" parameter for proper error checking.
      
      Signed-off-by: default avatarThomas Huth <thuth@redhat.com>
      Reviewed-by: default avatarIgor Mammedov <imammedo@redhat.com>
      Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
      04790978
  19. Nov 01, 2016
  20. Jul 20, 2016
  21. Jun 24, 2016
  22. Jan 29, 2016
    • Peter Maydell's avatar
      hw: Clean up includes · 0430891c
      Peter Maydell authored
      
      Clean up includes so that osdep.h is included first and headers
      which it implies are not included manually.
      
      This commit was created with scripts/clean-includes.
      
      Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
      Message-id: 1453832250-766-38-git-send-email-peter.maydell@linaro.org
      0430891c
  23. Dec 22, 2015
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